HD 54272, a classical lambda Bootis star and gamma Doradus pulsator

Article, Preprint English OPEN
Paunzen, E. ; Skarka, M. ; Holdsworth, D. L. ; Smalley, B. ; West, R. G. (2014)
  • Publisher: OXFORD UNIV PRESS
  • Journal: MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (issn: 0035-8711)
  • Related identifiers: doi: 10.1093/mnras/stu415
  • Subject: Astrophysics - Solar and Stellar Astrophysics | QB

We detect the second known lambda Bootis star (HD 54272) which exhibits gamma Doradus-type pulsations. The star was formerly misidentified as a RR Lyrae variable. The lambda Bootis stars are a small group (only 2 per cent) of late B to early F-type, Population I stars which show moderate to extreme (up to a factor 100) surface underabundances of most Fe-peak elements and solar abundances of lighter elements (C, N, O, and S). The photometric data from the Wide Angle Search for Planets (WASP) and All Sky Automated Survey (ASAS) projects were analysed. They have an overlapping time base of 1566 d and 2545 d, respectively. Six statistically significant peaks were identified (f1 = 1.410 116 c/d, f2 = 1.283 986 c/d, f3 = 1.293 210 c/d, f4 = 1.536 662 c/d, f5 = 1.157 22 c/d and f6 = 0.226 57 c/d). The spacing between f1 and f2, f1 and f4, f5 and f2 is almost identical. Since the daily aliasing is very strong, the interpretation of frequency spectra is somewhat ambiguous. From spectroscopic data, we deduce a high rotational velocity (250+-25 km/s) and a metal deficiency of about -0.8 to -1.1 dex compared to the Sun. A comparison with the similar star, HR 8799, results in analogous pulsational characteristics but widely different astrophysical parameters. Since both are lambda Bootis-type stars, the main mechanism of this phenomenon, selective accretion, may severely influence gamma Doradus-type pulsations.
  • References (7)

    Folsom C. P., Bagnulo S., Wade G. A., Alecian E., Landstreet J. D., Marsden S. C., Waite I. A., 2012, MNRAS, 422, 2072 Garrison R. F., Gray R .O., 1994, AJ, 107, 1556 Gray R. O., Garrison R. F., 1987, ApJS, 65, 581 Gray R. O., Garrison R. F., 1989a, ApJS, 69, 301 Gray R. O., Garrison R. F., 1989b, ApJS, 70, 623 Gray R. O., Corbally C. J., 1994, AJ, 107, 742 Gray R. O., Kaye A. B., 1999, AJ, 118, 2993 Gray R. O., Corbally C. J., Garrison R. F., McFadden M. T., Robinson P. E., 2003, AJ, 126, 2048 Hauck B., Mermilliod M., 1998, A&AS, 129, 431 Heiter U. et al., 2002, A&A 392, 619 Kamp I., Paunzen E., 2002, MNRAS, 335, L45 Lenz P., Breger M., 2004, Comm. Ast., 146, 53 Luck R. E., Heiter U., 2005, AJ, 129, 1063 Martinez-Galarza J. R., Kamp I., Su K. Y. L., Gáspár A., Rieke G., Mamajek E. E., 2009, AJ, 694, 165 Mestel L., Moss D., 2005, MNRAS, 361, 595 Michaud G., Charland Y., 1986, ApJ, 311, 326 Mikulášek Z., Krticˇka J., Henry G. W., de Villiers S. N., Paunzen E., Zejda, M. 2010, A&A, 511, L7 Moya A., Amado P. J., Barrado D., García Hernández A. G., Aberasturi M., Montesinos B., Aceituno F.„ 2010a, MNRAS, 405, L81

    Moya A., Amado P. J., Barrado D., García Hernández A. G., Aberasturi M., Montesinos B., Aceituno F., 2010b, MNRAS, 406, 566

    Paunzen E., 2001, A&A, 373, 633 Paunzen E. et al., 2002a, A&A, 392, 515 Paunzen E., Iliev I. Kh., Kamp I., Barzova I. S., 2002b, MNRAS, 336, 1030

    Philip A. G., Egret D., 1980, A&AS, 40, 199 Pojman´ski G., 1997, AcA, 47, 467 Pojman´ski G., 2001, IAU Colloq. 183: Small Telescope Astronomy on Global Scales, 246, 53 Pollacco D. L. et al., 2006, PASP, 118, 1407 Preston G. W., 1971, PASP, 83, 571 Rees D. G., 1987, Foundations of Statistics, Chapman & Hall, London

    Robitaille T. P., Whitney B. A., Indebetouw R., Wood K., 2007, ApJS, 169, 328

    Royer F., Zorec J., Gómez A. E. 2007, A&A, 463, 671 Sadakane K., 2006, PASJ, 58, 1023 Skarka M., 2013, A&A, 549, A101 Slettebak A., Kuzma T. J., Collins G. W., II, 1980, ApJ, 224, 171 Smith H. A., 2003, RR Lyrae Stars, Cambridge University Press, Cambridge

    Stibbs, D. W. N., 1950, MNRAS, 110, 395 Szczygieł D. M., Fabrycky D. C., 2007, MNRAS, 377, 1263 Takeda Y., Han I., Kang D.-I., Lee B.-C., Kim K.-M., 2008, Journal of Korean Astronomical Society, 41, 83 Zerbi F. M. et al., 1999, MNRAS, 303, 275 Zorec J., Royer F., 2012, A&A, 537, A120 Zuckerman B., Rhee J. H., Song I., Bessell M. S., 2011, ApJ, 732, 61

  • Metrics
    No metrics available
Share - Bookmark